First trip to Italy with grandaughter

What a terrific treat for your granddaughter! You can see quite a lot of Italy in 20 days (or 18, if the 20 includes day of arrival and day of departure).

Given your round-trip flight to Milan, I like your plan to drive to the lakes and Dolomites and hike around. But, you will want to get rid of the car in Venice (as you indicated) and yet a car would be useful for seeing Tuscany. You can visit many of the towns in Tuscany and surrounding regions such as Umbria by train and bus, it's just not as convenient.

Skip Rome? Hey, if you're not a fan of big cities, why force yourself to go there? Frankly I might be nervous touring Rome with a 13-year-old in tow, just as I would in the touristy areas of New York or Chicago. (I'm not saying it's unsafe, just that it might be a bit stressful for you as the only adult.)

Does your granddaughter have any particular interests in, say, art or music or ancient history or Italian language? If so, let us know and I'm sure some on this site will have suggestions in line with same.

Is this also your first trip to Italy? What a lucky grandchild.
Will you spend some time in Milan? The Dolomites will be fabulous! Stunning beauty and excellent hiking. Lake Como ( we love it but never took kids there as it is mainly looking at scenery, villas and gardens and we thought they'd be bored). Venice , Tuscany with Florence, perhaps as a day trip. Both of you can read "The Agony and the Ecstasy"(Michelangelo) before visiting Florence.
Look at staying in Siena as a base or in nearby Castellina, Panzano, Greve, Radda Easy to do day trips from Siena and surrounding towns..Our kids also liked Lucca and Volterra a lot. I would add Rome over the Cinque Terre with it's crowds in such a tiny place. Hiking is what Cinque Terre is all about but doing it in a mob is not my idea of fun. We went years ago and hiked the whole trail , all five villages.
You could easily add Lake Garda and Verona, Padua on the way to or from Venice and the Dolomites..Look at Hotel Castello with a beach in Malcesine on Lake Garda. We stayed there on our back from the Dolomites. There is an amusement park on Lake Garda too.
I hate to see you skip Rome with it's educational offerings but it is your trip and decision. If you stay in a comfortable neighborhood it might suit you better. Hire private guides too.

It will be a great trip. Be aware that the Italian male teenagers have a rather more aggressive take on pretty young 13 year old girls than she is probably used to coming from Alabama. Nothing weird, but she can expect to be subject of many longing glances by the high school set. My own 13 year old daughter loved it, and blushed and smiled her way through the attention, but if you aren't prepared for it, it can be disconcerting. At least it was disconcerting for dad.

How cool! If you don’t want to go to Rome don’t go to Rome. It sounds like you like smaller towns then I would go there. I saw the one note about Italian boys ogling a young girl. My daughter has been to Italy including Rome twice and had not had that happen to her. Maybe lucky or maybe just didn’t notice it. Of course we are from a big city and my daughter has traveled often.

I would ask your 13 year old granddaughter her input on where to go. Less is more. I would stay at each place a min of three nights. Enjoy!

I hope someone with spring experience in the Dolomites can comment on whether you'd do better to hit that area later in your trip rather than earlier--from the weather standpoint, I mean. Temperatures drop as altitude increases. Having only been there during mid-summer, I wouldn't know what to expect in late May.

I would leave the Dolomites to the end because trails can be muddy earlier on. Also the hiking is strenuous, and you don't want to get to Venice exhausted. She might like a quick trip to Bolzano to see Ötzi.

Spend at last 2 full days in Venice. Consider a gondola-rowing lesson. Instead of tootling around Tuscany (car is inconvenient because of the ZTLs in the historic town centers), you could stay in Bologna and day-trip by train to towns like Padua, Modena, Ferrara, even Ravenna. Ferrara and Ravenna are good places to rent bikes for the day. Find a cooking class in Bologna.

In recent years the CT has become so overcrowded, it's not a great destination. Some have suggested staying farther north on the Italian Riviera instead.

I like the idea of introducing your grandaughter to the Renaissance in Florence for 2-3 days (perhaps less crowded on weekdays). And if she really really doesn't warm to it, there are day trips to Siena by bus and to Pisa/Lucca by train.

Let her (and yourself) have a rest in the middle (a vacation from the vacation) where you do something childish - for your sake - definitely not for hers - she is grown up after all - lol

One suggestion: https://www.italiainminiatura.com/

For timing I think you should start by going by train to Venice - not a good idea to rent a car from day one, unless you are absolutely sure you don't suffer from jet lag after your flight.

Then rent a car for touring the country side.

Then drop the car and go to Florence. Take day trips by bus to Volterra, Lucca, and Siena

Here are a few random thoughts.

We have flown into & out of Milan before. I also rented a car there and drove to Lake Como. Be sure to rent your car in an area outside the ZTL of Milan. (I made a wrong turn the day we left, and but for a U-turn would have entered the ZTL. They are well sign posted however.) We kept the car with us of the 18 day trip. Tuscany is seen more efficiently by car IMHO. If you stayed outside Florence in an agriturismo you don't have to worry about the ZTL in Florence. (We stayed in Florence around the corner from the Duomo & they assisted in notifying the police when we checked in to allow us to drive into the ZTL. I still worried about it until we left Florence. Siena, San Gimignano, Volterra, etc. You can also visit the American Cemetery about 7 miles south of Florence where WWII soldiers are buried. It is a really moving place. I would also suggest doing the bike ride around the Lucca city wall. Your granddaughter & you might like this activity. You can rent your bikes close to the train station. We parked on the square across the street from the town wall and were on top of the wall in no time. You can also get a tour of the marble quarries in Carrara just up the road from Lucca & Pisa. If you go to Pisa, your granddaughter might enjoy climbing the leaning tower. (If they still let you do that.) Hope this gives you a few ideas.

Agree with suggestion to take train to Venice upon arrival in Milan. Venice is a great place to get over jet lag, acclimate to a new environment, and start the trip in a truly unique city. Also agree with the idea of getting her involved in the planning. Her interest may surprise you. The suggestion of spending at least three nights is one place is sound. It's amazing how much time is lost every time you change locations. It's not just the actual travel time, but also the time spent packing up, checking out of the hotel, locating the new hotel, checking in, unpacking, and so forth.

Thank you all so much the great suggestions! I will definitely try to stay 3 or 4 nights in each place. It will be my first trip also as well as my husbands. Since you commented saving the dolomites till the end of the trip because of the weather what do you think about heading straight to tuscany first by train or easy jet or maybe stay in Orvieta and day to trip to Rome the first couple of days. Then work our way back up? My grandaughter has said she would like to see Pompeii and I know that will be a long long day trip if even possible. Secondly, do you think the CT will really be that crowded in May/first of June? I would hate to miss it but you are right hiking in a mob is not my idea of fun either. I like the idea of staying in Siena, Castellina, or Panzano. I think an agritourisimo would be nice. Any recommendations? In any case, I think you've given me many ideas to work with to make this an unforgettable trip of a lifetime!

...or maybe stay in Orvieta and day to trip to Rome the first couple
of days. Then work our way back up? My grandaughter has said she would
like to see Pompeii and I know that will be a long long day trip if
even possible. Secondly, do you think the CT will really be that
crowded in May/first of June?

Nell, you're sort of adding to an already full pile here! :O)
IMHO, if you want to spend several days exploring Rome, I would stay IN Rome and not day-trip it from Oriveto. Some of the best hours for walking about are early mornings and the evenings, and there's a bonus to having your accommodation within shoutin' distance should you forget something or need a short break.

Pompeii is really only possible to daytrip from Rome and even then will be a long-ish day. I wouldn't try and do it from Orvieto: you're looking at at least 6 hours (probably more) RT on trains from there with multiple changes. Also, for a look at an interesting excavation, Ostia Antica is much less time-consuming from Rome. Additionally a hike on the Appia Antica is great fun and very interesting: our favorite day out in Rome to date! Biking is possible on that one as well although we personally preferred to hoof it.

Will the CT be crowded in late May/early June? Yes. That will not apply to ALL of the park's trails but it will to the midday hours in the villages and the two segments of the very popular Sentiero Azzurro (Blue Path) trail route (Monterosso>Vernazza>Corniglia) which are likely to be open this season.

Nell, try this itinerary.

Train: https://www.trenitalia.com/tcom-en

Arrive Milan MXP Train. Edit: Malapensa Express to Milano Centrale. 52 minutes.
To Florence
(Milan Centrale-Firenze SMN.) 2Hr51 min.

4 Nites Florence.
2 full days Florence , day trip to Lucca & Pisa by train.

Florence-Cinque Terre.
(Firenze SMN-La Spezia) 2Hr22min.
Cinque Terre Express-village of choice 8-28m.

3 Nites Cinque Terre.
Hiking and exploring villages by bus or ferry.

CT Express-La Specia. Rent car. Taxi to rental.
https://www.autoeurope.com
Things to know before you rent a car. Download their e-book.

https://www.italybeyondtheobvious.com/dont-mess-with-ztl-zones
You also need an IDP which is a translation of your home drivers license. $25 at AAA.

Day trip on way... Volterra. 1Hr49m.
Volterra-San Gimignano. 35m.
San Gimignano -Castellina 40 minutes.

3 Nites Castellina in Chianti.

Day trips, choose 2. (1) Greve, Panzano, Radda.
(2) Siena. (3) Bike ride from Siena-Montereggioni.

Castellina-Venice. 3Hr15m. You have to decide here if you want to keep the car and pay €32
A day parking or do the math to see if a 10 day rental offsets the parking fees.

3 Nites Venice.
Free tour. http://www.venicefreetours.com/la-bussola-association/

https://rowvenice.org/rv-venetian-rowing-lessons/

Vaporetto pass. https://quickvenice.com/transportation/actv-tourist-travel-cards.htm Lots of other useful info too.

Train: Venezia S.Lucia-Bolzano 2Hr41m
bus to Ortisei. Or alpine town of choIce.
Or pick up another rental in Bolzano.

4 Nites Dolomites.
Hiking, scenery, lifts, more hiking.

Return to Bolzano visit the Ice Man before you...
http://www.iceman.it/en/

Train: Bolzano-Milano Centrale. 3Hr48m.

2 Nites Milan.
After check in visit the Duomo and rooftop Terrace. Galleria Vittorio Emanuel- shopping
Day 2, day trip to Varenna on Lake Como.

Last day. Travel. Flight home.

Wow! I'm blown away! I asked and yall delivered! THank you all so much for the fantastic suggestions and to gerri especially for the detailed itenerary! I feel I'm all set! Now just need to start reserving lodging. I am grateful for this forum and people like yall who take the time to help.

May I recommend Lucca? We took a fun cooking class with Chef Paulo and my daughter and I also really enjoyed biking around the walls surrounding the city. It is such a quaint town and not far from Florence and Pisa.